JS实现千位分隔符
只适用整数
function format (num) {
var reg=/\d{1,3}(?=(\d{3})+$)/g;
return (num + '').replace(reg, '$&,');
} function format(num){
num=num+'';//数字转字符串
var str="";//字符串累加
for(var i=num.length- 1,j=1;i>=0;i--,j++){
if(j%3==0 && i!=0){//每隔三位加逗号，过滤正好在第一个数字的情况
str+=num[i]+",";//加千分位逗号
continue;
}
str+=num[i];//倒着累加数字
}
return str.split('').reverse().join("");//字符串=>数组=>反转=>字符串
}
整数部分加小数部分不动
let miliFormat = (() => {
let DIGIT_PATTERN = /(^|\s)\d+(?=\.?\d*($|\s))/g
let MILI_PATTERN = /(?=(?!\b)(\d{3})+\.?\b)/g
return (num) => num && num.toString()
.replace(DIGIT_PATTERN, (m) => m.replace(MILI_PATTERN, ','))
})()
保留两位小数（四舍五入-舍）
function milliFormat(num){//添加千位符
s=num.toString()
if(/[^0-9\.]/.test(s)) return "invalid value";
s=s.replace(/^(\d*)$/,"$1.");
s=(s+"00").replace(/(\d*\.\d\d)\d*/,"$1");
s=s.replace(".",",");
var re=/(\d)(\d{3},)/;
while(re.test(s)){
s=s.replace(re,"$1,$2");
}
s=s.replace(/,(\d\d)$/,".$1");
return s.replace(/^\./,"0.")
}
一套完整的金额转换加千位分隔符
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="zh-cn">
<head>
<title>js千位符 | js 千位分隔符 | js 金额格式化</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script type="text/javascript">
// 将金额类型转为数字类型
function toNum(str) {
return str.replace(/\,|\￥/g, "");
}
// 保留两位小数（四舍五入）
function toPrice(num) {
num = parseFloat(toNum(num)).toFixed(2).toString().split(".");
num[0] = num[0].replace(new RegExp('(\\d)(?=(\\d{3})+$)','ig'),"$1,");
return "￥" + num.join(".");
}
// 保留两位小数（不四舍五入）
function toPrice1(num) {
num = parseFloat(toNum(num).replace(/(\.\d{2})\d+$/,"$1")).toFixed(2).toString().split(".");
num[0] = num[0].replace(new RegExp('(\\d)(?=(\\d{3})+$)','ig'),"$1,");
return "￥" + num.join(".");;
}
// 不处理小数部分
function toPrice2(num) {
var source = toNum(num).split(".");
source[0] = source[0].replace(new RegExp('(\\d)(?=(\\d{3})+$)','ig'),"$1,");
return "￥" + source.join(".");
}
</script>
</head>
<body>
<h1>js千位符 | js 千位分隔符 | js 金额格式化</h1>
<div>
保留两位小数（四舍五入）: <input onchange="this.value=toPrice(this.value)"><br><br>
保留两位小数（不四舍五入）: <input onchange="this.value=toPrice1(this.value)"><br><br><br>
不处理小数部分: <input onchange="this.value=toPrice2(this.value)">
</div>
</body>
</html>
效果：